Thanks to Apple Tech Note - http://support.apple.com/kb/HT6311?viewlocale=en_US&locale=en_US
OS X: How to prevent OS X Beta installations
If users enroll in the OS X Beta program, their Macs may be offered pre-release Apple software. You can use Profile Manager to make sure that pre-release software is not offered to Macs using OS X.
Prevent OS X Beta installations
Follow these steps to block access to pre-release versions of OS X Yosemite available from the OS X Beta Program:
Use Profile Manager in OS X Server to create a Custom Settings payload.
Type in the preference domain name com.apple.SoftwareUpdate
Enter a key of AllowPreReleaseInstallation
Set the key's type to Boolean.
Leave the checkbox under the Value column deselected. This sets the key's value to False.
After saving these changes, push this profile out to your client systems. Macs using this profile can no longer install pre-release versions of OS X Yosemite from the OS X Beta Program.
If you’re not using Profile Manager, you can create your own profile. Download this file to see an example profile. Distribute your profile to your clients from an email message or a webpage. You can also use over-the-air profile delivery and configuration, or a Mobile Device Management server to distribute your profile.
These steps only block access to pre-release software from the OS X Beta Program. They do not prevent the installation of released versions of OS X.
This profile was created based on the directions in the KB article. I've tested it in my environment and when you try to install the beta a message will pop up saying, "The prerelease version of OS X Yosemite cannot be installed on this Mac due to the Software Update Policy in effect."
When trying to deploy this Configuration Profile it always gets stuck in "Pending Commands" when I look at the client machine's Management History in the JSS. (This may be an unrelated issue as this is the first time we've tried deploying a .mobileconfig.) Sending a Blank Push succeeds, but the pending commands do not execute during inventory or checkin.
Update: My issue turned out to be certificate and push settings, not the mobileconfig. Works great.
Posted Today at 3:55 PM by etippett Are local admin rights required to enroll in Beta? Hoping so I don't have to bother with setting up the profile...
Anyone can enrol in the beta if there is space left. They will still be able to download the installer.
However they will need admin rights to run the installer.